A Manhattan post office doesn’t specialize in snail mail — it specializes in no mail.

Morningside Heights residents hoping to mail out letters and packages before work Tuesday morning waited for more than an hour — a regular occurrence — before they even saw someone with a United States Postal Service uniform walk through the door at the 232 W. 116th St. location.

Countless residents recounted stories to The Post of arriving at the post office promptly at 8:30 a.m., when it’s supposed to open, only to stand on the street waiting.

“Every time I go there, I feel like I’ve been punked,” said Michele Scott, a 60-year-old-event planner who tries to avoid the post office “like a plague.”

Post office officials said the office has at least two windows open each business day.

But on Tuesday, a supervisor came out to inform the 15 people waiting that there would not be any window clerks working, although one worker filtered in an hour late and by the end of the day, there were three.

About five years ago, residents noticed the service took a turn for the worse.

“Everything was falling down,” said Elizabeth Johnson, 60.

“I’m dissatisfied with the service,” said Johnson. “This is the federal government. This is unacceptable.”

The West 116th Street location axed two positions sometime last year, and since then a lack of window service has become the norm, a local resident said.

“The service is lousy,” said 59-year-old Michelle Abbott-Smith, a church librarian who uses this post office at least twice a week.

“I don’t expect you to greet me with a song and dance and coffee and doughnuts, but I expect you go take my order politely and get me out of there as expeditiously as possible.”

Natalie Swanston, 65, headed to the post office a few weeks before Christmas to mail presents to her relatives in South Carolina, only to find the door locked.

“It was. 8:30 a.m. and I started banging on the door. It was cold outside,” said Swanston, who was late to her job as a home health aide.

Johnson waited an hour to mail a package to Ethiopia until she finally threw her hands up in the air and decided to go to another location.